How do the red giants of the new SySt compare to well established SySt ?
This is addressed in Fig. REF , where their distributions in
\(M(K_S)\)  are compared. For the well established SySt we adopted the catalog
by [1]}, and retained only the 44 objects with a
giant of M spectral type and with a Gaia \(e\) DR3 parallax accurate enough to
satisfy the inversion condition \(\sigma (\pi )\) /\(\pi \)\(<\) 0.2. To compute their
\(M(K_S)\)  we adopted for them the interstellar extinction estimated from the
Bayestar 2019 3D model of the Galaxy [2]}.
